Born in 1856, he went to work for the Atlantic and Pacific Railway when he was 17. At the age of 22 he became secretary to the Manager of the Missouri Pacific Railway. He married Clara Gregg in October 1881 and they went on to have four daughters.

In 1889 he was appointed general manager of the Wabash Railway network and then in 1896 he moved to Montreal and became the general manager of the Grand Trunk Pacific Railway. He would be influential in Canada, convincing the Prime Minister, Sir Wilfrid Laurier, of the need to build a second transcontinental route.  The Canadian government subsidised the project which began construction in November 1902 but the board of directors, back in England, started to express concern. In 1907 Hays was awarded Japan's highest order, the order of the Rising Sun by Prince Fushimi. In 1910 he turned down the offer of a knighthood as it would require him to surrender his American citizenship. As his transcontinental project continued to grow the haphazard financing meant that by 1911 the company was in serious debt. Hays travelled to England to meet the directors and proposed to invest in infrastructure to turn fortunes around. 

It was noted by a member of the board that Hays looked tired when he arrived in England. He planned to spend Easter in Paris with Orian, his daughter, and his son in law, Thornton Davidson. but he stayed at Smithers country estate in Kent instead. During his stay he received news that another daughter, Louise, was having a difficult preganancy and the imminent opening of the Château Laurier Hotel was scheduled for April 26. Travelling with him was the sculptor Paul Romaine Chevré, who had done the bust of Laurier that can be found on the lobby of that hotel to this day. 

Hays was actually in negotiations with White Star Line regarding offers for trips to the Far East via White Star Line shipping and his transcontinental line. It is understood that J. Bruce Ismay  President of White Star Line, invited Hays and his party as guests aboard the Titanic. He paid  £93 10s to cover expenses and travelled with his wife, his daughter and son in law, thier maid Miss Perreault and Hays secretary, Vivian Payne. The party occupied four cabins in total. 

Just an hour before the collision, Hays was relaxing with Colonel Archibald Gracie and Captain Edward Crosby in the Gentleman's Smoking Lounge. Their conversation revolved around the technological developments in transportation. It is reported that Hays commented "the trend to playing fast and loose with larger and larger ships will end in tragedy." Hays did not imagine the ship would sink so quickly, he put his wife and daughter into a lifeboat and assured them the ship would stay "afloat for at least 10 hours."

Hays drowned in the disaster. His body was recovered and transported to Montreal for burial aboard his private railroad car, which is still preserved on display at the Canadian Railway Museum near Delson, Quebec. 

There were two simultaneous funeral services held in Montreal and London, England. On the day of the funeral the Montreal Herald reported:

"From Montreal to Chicago, from New Brunswick to the Pacific coast, in  all the thousands of miles of sidings and branch lines owned and  operated by the Grand Trunk Railway, in every Grand Trunk Depot, at  every Grand Trunk crossing, action ceased for the space of five full  minutes as the Grand Trunk Railway system paid its respects to the  memory of its great departed chief. For five minutes activities were  suspended and the thousands of individuals who serve the great system  invarious capacities bowed their heads in silent tribute. Then once more  work resumed, the wheels turned, and in 30 seconds things had been as  they had before."

He was buried in the Mount Royal Cemetery in Montreal. The monument to him is inscribed: "And so he died and the example of his simple, devoted consecrated life  is our priceless heritage. We are a different people, we are a better  people, because this man worked and loved and died."

The Canadian towns of Hays in Alberta and Melville in Saskatchewan are named after him, and a statue of him was erected in Prince Rupert, British Colombia, which was to have been the Pacific terminus of the transcontinental project. The Grand Trunk Railroad went into recievership in 1919 and became part of Canadian National Railways.